Polymerisation catalyst

ABSTRACT

A complex of transition metal Ti, Fe, Co, Ni, Cr, Mn, Ta, Rh, Y, Sc, Ru, Pd, Zr, Hf, V or Nb and a mono-, bi-, tri-, or tetra-dentate ligand, wherein at least one of the donor atoms of the ligand is a nitrogen atom N with a 5-membered heterocyclic substituent joined to the N by a carbon atom. The complex is preferably formula (I) wherein R 5 —N-G-X 1  is a bi-, tri. or tetra-dentate ligand, N is joined to G by an imine linkage; G is a bridging group which can contain a third or fourth donor atom; X 1  is —O or —S if the X 1 -M bond is covalent, or if the X 1 -M bond is dative X 1  is ═S, —PR 7 R 8 , —PR 8 R 9 , ═NR 7 , ═NR 8 , —NR 7 R 8  or —NR 8 R 9 : R 5  and R 7  are 5-membered heterocyclic substituents joined to the nitrogen (or phosphorus) atoms via a carbon atom: R 8  and R 9  are hydrocarbyl or heterohydrocarbyl, substituted hydrocarbyl or aryl substituent; X represents an atom or group covalently or ionically bonded to the transition metal M; L is a group datively bound to M, and n is from 0 to 5; q is 1 or 2. The complexes find use as polymerisation catalysis, preferably with an activator, e.g. MAO.

[0001] The present invention relates to transition metal complexcompounds, to polymerisation catalysts based thereon and to their use inthe polymerisation and copolymerisation of olefins.

[0002] The use of certain transition metal compounds to polymerise1-olefins, for example, ethylene or propylene, is well established inthe prior art. The use of Ziegler-Natta catalysts, for example, thosecatalysts produced by activating titanium halides with organometalliccompounds such as triethylaluminium, is fundamental to many commercialprocesses for manufacturing polyolefins. Over the last twenty or thirtyyears, advances in the technology have led to the development ofZiegler-Natta catalysts which have such high activities that olefinpolymers and copolymers containing very low concentrations of residualcatalyst can be produced directly in commercial polymerisationprocesses. The quantities of residual catalyst remaining in the producedpolymer are so small as to render unnecessary their separation andremoval for most commercial applications. Such processes can be operatedby polymerising the monomers in the gas phase, or in solution or insuspension in a liquid hydrocarbon diluent. Polymerisation of themonomers can be carried out in the gas phase (the “gas phase process”),for example by fluidising under polymerisation conditions a bedcomprising the target polyolefin powder and particles of the desiredcatalyst using a fluidising gas stream comprising the gaseous monomer.In the so-called “solution process” the (co)polymerisation is conductedby introducing the monomer into a solution or suspension of the catalystin a liquid hydrocarbon diluent under conditions of temperature andpressure such that the produced polyolefin forms as a solution in thehydrocarbon diluent. In the “slurry process” the temperature, pressureand choice of diluent are such that the produced polymer forms as asuspension in the liquid hydrocarbon diluent. These processes aregenerally operated at relatively low pressures (for example 10-50 bar)and low temperature (for example 50 to 150° C.).

[0003] In recent years the use of certain metallocene catalysts (forexample biscyclopentadienylzirconiumdichloride activated with alumoxane)has provided catalysts with potentially high activity. However,metallocene catalysts of this type suffer from a number ofdisadvantages, for example, high sensitivity to impurities when usedwith commercially available monomers, diluents and process gas streams,the need to use large quantities of expensive alumoxanes to achieve highactivity, and difficulties in putting the catalyst on to a suitablesupport.

[0004] An object of the present invention is to provide a novel catalystsuitable for polymerising and oligomerising monomers, for example,olefins such as α-olefins containing from 2 to 20 carbon atoms, andespecially for polymerising ethylene alone, propylene alone, or forcopolymerising ethylene or propylene with other 1-olefins such as C₂₋₂₀α-olefins.

[0005] WO 99/12981 discloses that ethylene and other 1-olefins may bepolymerised by contacting it with certain late transition metalcomplexes of selected 2,6-pyridinecarboxaldehydebis (imines) and2,6-diacylpyridinebis (imines).

[0006] WO 00/50470 discloses in its broadest aspect a polymerisationcatalyst comprising a transition metal complex in which at least one ofthe donor atoms of the ligand is a nitrogen atom substituted by a1-pyrrolyl or substituted 1-pyrrolyl group. Specific examples includeligands such as the following, where the R groups are typically alkylgroups:

[0007] WO01/14391 discloses similar bisiminidato metal complexes inwhich two of the donor atoms of the ligand are nitrogen atoms linked tofurther nitrogen atoms of a substituent which may be a five-memberedheterocyclic substituent.

[0008] The chemistry of C—N bonds is well-known to be significantlydifferent to that of N—N bonds, including the type exemplified byN-iminopyrrole examples in the prior art. In particular, ligandscontaining N-donor atoms linked to a C atom would be expected tocontribute a different amount of electronic charge to the metal centrecompared with an N donor linked to another N atom, and this is likely tohave a significant effect on the overall catalytic properties of thecomplex.

[0009] We have discovered a further class of complexes that areeffective polymerisation catalysts in which at least one, preferably twoof the donor atoms of the ligand is a nitrogen atom joined to a carbonatom of a five-membered heterocyclic substituent.

[0010] Accordingly in its broadest aspect, the present inventionprovides a metal complex being Ti[II], Ti[III], Ti[IV], Fe[II], Fe[II],Co[II], Co[III], Ni[II], Cr[II], Cr[III], Mn[II], Mn[III], Mn[IV],Ta[II], Ta[III], Ta[IV], Rh[II], Rh[III], Y[II], Y[III], Sc[II],Sc[III], Ru[II], Ru[III], Ru[IV], Pd[II], Zr[II], Zr[III], Zr[IV],H[II], Hf[III], Hf[IV], V[II], V[III], V[IV], Nb[II], Nb[III], Nb[IV] orNb[V], ligated by a monodentate, bidentate, tridentate or tetradentateligand, wherein at least one of the donor atoms of the ligand is anitrogen atom substituted by a five-membered heterocyclic substituentjoined to the nitrogen atom by a carbon atom.

[0011] Preferably the complex is of the Formula (I)

[0012] wherein the structure R⁵—N-G-X′ represents a bidentate,tridentate or tetradentate ligand, in which N is a nitrogen joined to Gby an imine linkage; 4 is a bridging group which optionally contains athird or fourth donor atom; XI is −0 or —S if the Xl-M bond is covalent,or if the X¹-M bond is dative X¹ is —S, —PR⁷R⁸, —PR⁸R⁹, ═NR⁷, ═NR⁸,—NR⁷R⁸ or —NR⁸R⁹; R⁵ is a five-membered heterocyclic substituent joinedto the nitrogen atom via a carbon atom; R⁷ is a five-memberedheterocyclic substituent joined to the nitrogen or phosphorus atom via acarbon atom; and R⁸ and R⁹ are hydrocarbyl or heterohydrocarbyl,substituted hydrocarbyl or aryl substituent; M is Ti[II], Ti[III],Ti[IV], Fe[II], Fe[III], Co[II], Co[III], Ni[II], Cr[II], Cr[III],Mn[II], Mn[III], Mn[IV], Ta[II], Ta[III], Ta[IV], Rh[II], Rh[III],Y[II], Y[III], Sc[II], Sc[III], Ru[II], Ru[III], Ru[IV], Pd[II], Zr[II],Zr[II], Zr[IV], Hf[II], Hf[III], HF[IV], V[II], V[III], V[IV], Nb[II],Nb[III], Nb[IV], Nb[V]; X represents an atom or group covalently orionically bonded to the transition metal M; and L is a group dativelybound to M, and n is from 0 to 5; q is 1 or 2.

[0013] Preferably X¹ is ═NR¹. In the case where q is 2, the two ligandsmay be joined to form a single tetradentate ligand. However preferably qis 1, and the ligand is bidentate or tridentate.

[0014] Preferably R⁵ and R⁷ each independently have the structure

[0015] wherein D, W, Y and Z are each independently selected from CR,CRR′, N, NR, O, S, PR or PRR′ where R and R′ are each independently H,C₁-C₁₀ alkyl, C₁-C₁₀ heteroalkyl or C₆-C₂₀ aryl or aralkyl, with theproviso that at least one of D, W, Y and Z is not CR or CRR′. It ispreferred that the ring is heteroaromatic, with two of D, W, Y and Zbeing CR, and the other two being independently selected from N, NR, Oor S.

[0016] Preferably one or both of the R⁵ and R⁷ rings are substituted atone or both positions adjacent the linkage to the nitrogen atom. Suchsubstituents are preferably methyl, ethyl, isopropyl or phenyloptionally substituted with C₁-C₄ alkyl. A preferred structure for R⁵and R⁷ is the following:

[0017] where D¹ is NR, O or S where R is H, C₁-C₆ alkyl or C₆-C₂₀ arylor aralkyl, and two of W¹, Y¹ and Z¹ are independently H, C₁-C₆ alkyl orC₆-C₂₀ aryl or aralkyl, whilst the third is replaced by a direct bond tothe nitrogen atom to which R⁵ or R⁷ is attached. Preferably Y¹ isreplaced by the bond to the nitrogen atom. Preferably W¹ and Z¹ areC₁-C₆ alkyl or C₆-C₂₀ aryl or aralkyl. Preferably D¹ is NR.

[0018] A particularly preferred substituent for both R⁵ and R⁷ is thesubstituent having the formula (II):

[0019] Generally, the above five-membered heterocyclic substituent mayreplace a pyrrolyl or substituted pyrrolyl substituent attached to adonor nitrogen atom in any of the complexes disclosed in WO 00/50470.

[0020] A second aspect of the invention comprises a complex representedby the general formula (1)

[0021] wherein M is Ti[II], Ti[III], Ti[IV], Fe[II], Fe[II], Co[II],Co[II], Ni[II], Cr[II], Cr[III], Mn[II], Mn[III], Mn[IV], Ta[II],Ta[II], Ta[IV], Rh[II], Rh[III], Y[II], Y[II], Sc[II], Sc[III], Ru[II],Ru[III], Ru[IV], Pd[II], Zr[II], Zr[III], Zr[IV], Hf[II], Hf[III],Hf[IV], V[II], V[III], V[IV], Nb[II], Nb[III], Nb[IV], Nb[V]; Xrepresents an atom or group covalently or ionically bonded to thetransition metal M; Y¹ is C or P(R^(c)); Y² is —O(R⁷), —O (in which casethe bond from 0 to M is covalent), —C(R)═O, —C(R^(b))═N(R⁷),—P(kb)(R^(d))═N(R⁷) or —P(R)(R^(d))═O; R⁵ and R⁷ are each independentlyfive-membered heterocyclic substituents joined to the nitrogen atom viaa carbon atom; R^(a), R^(b), R¹, R^(d) are each independently selectedfrom hydrogen, halogen, hydrocarbyl, substituted hydrocarbyl,heterohydrocarbyl, substituted heterohydrocarbyl or SiR′₃ where each R′is independently selected from hydrogen, halogen, hydrocarbyl,substituted hydrocarbyl, heterohydrocarbyl and substitutedheterohydrocarbyl, and any adjacent ones maybe joined together to form aring; G is either a direct bond between Y¹ and Y², or is a bridginggroup which optionally contains a third atom linked to M when q is 1; Lis a group datively bound to M; n is from 0 to 5; and q is 1 or 2.

[0022] Preferably the above complex has the formula (IV)

[0023] wherein M is Ti[II], Ti[III], Ti[IV], Fe[II], Fe[III], Co[II],Co[III], Ni[II], Cr[II], Cr[III], Mn[II], Mn[III], Mn[IV], Ta[II],Ta[II], Ta[IV], Rh[II], Rh[III], Y[II], Y[III], Sc[II], Sc[III], Ru[II],Ru[III], Ru[IV], Pd[II], Zr[II], Zr[III], Zr[IV], Hf[II], Hf[III],Hf[IV], V[II], V[III], V[IV], Nb[II], Nb[III], Nb[IV], Nb[V]; Xrepresents an atom or group covalently or ionically bonded to thetransition metal M; R^(a), R^(b) and R^(x) are each independentlyselected from hydrogen, halogen, hydrocarbyl, substituted hydrocarbyl,heterohydrocarbyl, substituted heterohydrocarbyl or SiR′₃ where each R′is independently selected from hydrogen, halogen, hydrocarbyl,substituted hydrocarbyl, heterohydrocarbyl and substitutedheterohydrocarbyl, and R^(a) and R^(b) may be joined together to form aring; R⁵ is a five-membered heterocyclic substituent joined to thenitrogen atom via a carbon atom; and L is a group datively bound to M; nis from 0 to 5; and q is 1 or 2.

[0024] Preferably M is a Group IV metal, particularly Ti, Zr, Cr, Ni orPd. Preferably R^(a) and R^(b) are joined together to form a phenyl,which is preferably substituted. Preferred substituents are C₁-C₆ alkylor C₆-C₂₄ aryl or aralkyl. In particular, the phenyl group may besubstituted at the position adjacent the oxygen linkage with a t-butylgroup or an anthracenyl group, which may itself be substituted.

[0025] An alternative preferred complex of the invention has the Formula(V)

[0026] wherein R⁵ and R⁷ are each independently five-memberedheterocyclic substituents joined to the nitrogen atom via a carbon atom;R^(a), and R^(b) are each independently selected from hydrogen, halogen,hydrocarbyl, substituted hydrocarbyl, heterohydrocarbyl, substitutedheterohydrocarbyl or SiR′₃ where each R′ is independently selected fromhydrogen, halogen, hydrocarbyl, substituted hydrocarbyl,heterohydrocarbyl and substituted heterohydrocarbyl, and R^(a) and R^(b)may be joined together to form a ring; M is TI[II], Ti[III], Ti[IV],Fe[II], Fe[III], Co[II], Co[III], Ni[III], Cr[II], Cr[III], Mn[II],Mn[III], Mn[IV], Ta[II], Ta[III], Ta[IV], Rh[II], Rh[III], Y[II],Y[III], Sc[II], Sc[III], Ru[II], Ru[III, Ru[IV], Pd[II], Zr[II],Zr[III], Zr[IV], Hf[II], Hf[III], Hf[IV], V[II], V[III], V[IV], Nb[II],Nb[III], Nb[IV], Nb[V]; X represents an atom or group covalently orionically bonded to the transition metal M; L is a group datively boundto M; n is from 0 to 5; and q is 1 or 2; and G¹ is either a direct bondbetween the two C═N groups, or is a bridging group which optionallycontains a third donor atom when q is 1.

[0027] An example of the above is the complex of Formula (VI):

[0028] wherein M is Ti[II], Ti[III], Ti[IV], Fe[II], Fe[III], Co[II],Co[III], Ni[II], Cr[II], Cr[III], Mn[II], Mn[III], Mn[IV], Ta[II],Ta[III], Ta[IV], Rh[II], Rh[III], Y[II], Y[III], Sc[II], Sc[III],Ru[II], Ru[III], Ru[IV], Pd[II], Zr[II], Zr[III], Zr[IV], Hf[II],Hf[III], HF[IV], V[II], V[III], V[IV], Nb[II], Nb[III], Nb[IV], Nb[V]; Xrepresents an atom or group covalently or ionically bonded to thetransition metal M; RB and R^(b) are each independently selected fromhydrogen, halogen, hydrocarbyl, substituted hydrocarbyl,heterohydrocarbyl, substituted heterohydrocarbyl or SiR′₃ where each R′is independently selected from hydrogen, halogen, hydrocarbyl,substituted hydrocarbyl, heterohydrocarbyl and substitutedheterohydrocarbyl, and R^(a) and R^(b) may be joined together to form aring; wherein R⁵ and R⁷ are each independently five-memberedheterocyclic substituents joined to the nitrogen atom via a carbon atom;and L is a group datively bound to M; n is from 0 to 5; and q is 1 or 2.

[0029] Preferably M is Ni or Pd.

[0030] A particularly preferred complex has the following Formula (VU)

[0031] wherein M is Ti[II], Ti[III], Ti[IV], Fe[II], Fe[III], Co[II],Co[III], Ni[II], Cr[II], Cr[III], Mn[II], Mn[III], Mn[IV], Ta[II],Ta[III], Ta[IV], Rh[II], RH[III], Y[II], Y[III], Sc[II], Sc[III],Ru[II], Ru[III], Ru[IV], Pd[II], Zr[II], Zr[III], Zr[IV], Hf[II],Hf[III], HF[IV], V[II], V[III], V[IV], Nb[II], Nb[III], Nb[IV], Nb[V]; Xrepresents an atom or group covalently or ionically bonded to thetransition metal M; T is the oxidation state of the transition metal Mand b is the valency of the atom or group X; A¹ to A³ are eachindependently N or P or CR, with the proviso that at least one is CR; R,R⁴ and R⁶ are each independently selected from hydrogen, halogen,hydrocarbyl, substituted hydrocarbyl, heterohydrocarbyl, substitutedheterohydrocarbyl or SiR′₃ where each R¹ is independently selected fromhydrogen, halogen, hydrocarbyl, substituted hydrocarbyl,heterohydrocarbyl and substituted heterohydrocarbyl; and R¹ and R⁷ areeach independently five-membered heterocyclic substituents joined to thenitrogen atom via a carbon atom.

[0032] Preferably A¹ to A³ are each independently CR where each R is asdefined above. In alternative preferred embodiments, A¹ and A³ are bothN and A² is CR, or one of A¹ to A³ is N and the others are independentlyCR.

[0033] The metal M is preferably Fe(II), Fe(m) or Co(II).

[0034] Each of the nitrogen atoms is coordinated to the metal M by a“dative” bond, i.e. a bond formed by donation of a lone pair ofelectrons from the nitrogen atom. The remaining bonds on each nitrogenatom are covalent bonds formed by electron sharing between the nitrogenatoms and the organic ligand as shown in the defined formula for thetransition metal complex illustrated above.

[0035] The atom or group represented by X in the above complexes can be,for example, selected from halide, sulphate, nitrate, thiolate,thiocarboxylate, BF₄ ⁻, PF₆ ⁻, hydride, hydrocarbyloxide, carboxylate,hydrocarbyl, substituted hydrocarbyl and heterohydrocarbyl, orβ-diketonates. Examples of such atoms or groups are chloride, bromide,methyl, ethyl, propyl, butyl, octyl, decyl, phenyl, benzyl, methoxide,ethoxide, isopropoxide, tosylate, triflate, formate, acetate, phenoxideand benzoate. Preferred examples of the atom or group X are halide, forexample, chloride, bromide; hydride; hydrocarbyloxide, for example,methoxide, ethoxide, isopropoxide, phenoxide; carboxylate, for example,formate, acetate, benzoate; hydrocarbyl, for example, methyl, ethyl,propyl, butyl, octyl, decyl, phenyl, benzyl; substituted hydrocarbyl;heterohydrocarbyl; tosylate; and triflate. Preferably X is selected fromhalide, hydride and hydrocarbyl. Chloride is particularly preferred.

[0036] L may be for example an ether such as tetrahydrofuran ordiethylether, an alcohol such as ethanol or butanol, a primary,secondary or tertiary amine, or a phosphine.

[0037] The complexes of the present invention may be used as catalystsfor the polymerisation of 1-olefins, optionally in conjunction with anactivator compound. For example the catalysts can be used for thepolymerisation of 1-olefins, or the copolymerisation of one or more1-olefins optionally with other unsaturated monomer. The term“polymerisation” as used throughout this specification is intended toinclude homopolymerisation, copolymerisation and oligomerisation.

[0038] The activator compound for all the catalysts of the presentinvention is suitably selected from organoaluminium compounds andhydrocarbylboron compounds. Suitable organoaluminium compounds includecompounds of the formula AlR₃, where each R is independently C₁-C₁₂alkyl or halo. Examples include trimethylaluminium (TMA),triethylaluminium (TEA), tri-isobutylaluminium (TIBA),tri-n-octylaluminium, methylaluminium dichloride, ethylaluminiumdichloride, dimethylaluminium chloride, diethylaluminium chloride,ethylaluminiumsesquichloride, methylaluminiumsesquichloride, andalumoxanes. Alumoxanes are well known in the art as typically theoligomeric compounds which can be prepared by the controlled addition ofwater to an alkylaluminium compound, for example trimethylaluminium.Such compounds can be linear, cyclic or mixtures thereof. Commerciallyavailable alumoxanes are generally believed to be mixtures of linear andcyclic compounds. The cyclic alumoxanes can be represented by theformula [R¹⁶AlO)] and the linear alumoxanes by the formula R¹⁷(R¹⁸AlO),wherein s is a number from about 2 to 50, and wherein R¹⁶, R¹⁷, and R¹⁸represent hydrocarbyl groups, preferably C₁ to C₆ alkyl groups, forexample methyl, ethyl or butyl groups. Alkylalumoxanes such asmethylalumoxane (MAO) are preferred.

[0039] Mixtures of alkylalumoxanes and trialkylaluminium compounds areparticularly preferred, such as MAO with TMA or TIBA. In this context itshould be noted that the term “alkylalumoxane” as used in thisspecification includes alkylalumoxanes available commercially which maycontain a proportion, typically about 1 Owt %, but optionally up to 50wt %, of the corresponding trialkylaluminium; for instance, commercialMAO usually contains approximately 10 wt % trimethylaluminium (TMA),whilst commercial MMAO contains both TMA and T[BA. Quantities ofalkylalumoxane quoted herein include such trialkylaluminium impurities,and accordingly quantities of trialkylaluminium compounds quoted hereinare considered to comprise compounds of the formula AlR₃ additional toany AlR₃ compound incorporated within the alkylalumoxane when present.

[0040] Examples of suitable hydrocarbylboron compounds are boroxines,trimethylboron, triethylboron,dimethylphenylammoniumtetra(phenyl)borate, trityltetra(phenyl)borate,triphenylboron, dimethylphenylammonium tetra(pentafluorophenyl)borate,sodium tetraais[(bis-3,5-trifluoromethyl)phenyl]borate,H⁺(OEt₂)_(t)(bis-3,5-trifluoromethyl)phenyl]borate,trityltetra(pentafluorophenyl)borate and tris(pentafluorophenyl)boron.

[0041] In the preparation of the catalysts of the present invention thequantity of activating compound selected from organoaluminium compoundsand hydrocarbylboron compounds to be employed is easily determined bysimple testing, for example, by the preparation of small test sampleswhich can be used to polymerise small quantities of the monomer(s) andthus to determine the activity of the produced catalyst. It is generallyfound that the quantity employed is sufficient to provide 0.1 to 20,000atoms, preferably 1 to 2000 atoms of aluminium or boron per atom ofmetal M in the compound of Formula (I).

[0042] An alternative class of activators comprise salts of a cationicoxidising agent and a non-coordinating compatible anion. Examples ofcationic oxidising agents include: ferrocenium, hydrocarbyl-substitutedferrocenium, Ag⁺, or Pb²⁺. Examples of non-coordinating compatibleanions are BF₄ ⁻, SbF₆ ⁻, PF₆ ⁻, tetrakis(phenyl)borate andtetrakis(pentafluorophenyl)borate.

[0043] A further aspect of the present invention provides apolymerisation catalyst system comprising (1) a complex as hereinbeforedefined, (2) an activating quantity of at least one activator compoundas defined above, and (3) a neutral Lewis base.

[0044] Neutral Lewis bases are well known in the art of Ziegler-Nattacatalyst polymerisation technology. Examples of classes of neutral Lewisbases suitably employed in the present invention are unsaturatedhydrocarbons, for example, alkenes (other than 1-olefins) or alkynes,primary, secondary and tertiary amines, amides, phosphoramides,phosphines, phosphites, ethers, thioethers, nitrites, carbonylcompounds, for example, esters, ketones, aldehydes, carbon monoxide andcarbon dioxide, sulphoxides, sulphones and boroxines. Although 1-olefinsare capable of acting as neutral Lewis bases, for the purposes of thepresent invention they are regarded as monomer or comonomer 1-olefinsand not as neutral Lewis bases per se. However, alkenes which areinternal olefins, for example, 2-butene and cyclohexene are regarded asneutral Lewis bases in the present invention. Preferred Lewis bases aretertiary amines and aromatic esters, for example, dimethylaniline,diethylaniline, tributylamine, ethylbenzoate and benzylbenzoate. In thisparticular aspect of the present invention, components (1), (2) and (3)of the catalyst system can be brought together simultaneously or in anydesired order. However, if components (2) and (3) are compounds whichinteract together strongly, for example, form a stable compoundtogether, it is preferred to bring together either components (1) and(2) or components (1) and (3) in an initial step before introducing thefinal defined component. Preferably components (1) and (3) are contactedtogether before component (2) is introduced. The quantities ofcomponents (1) and (2) employed in the preparation of this catalystsystem are suitably as described above in relation to the catalysts ofthe present invention. The quantity of the neutral Lewis Base [component(3)] is preferably such as to provide a ratio of component (1):component (3) in the range 100:1 to 1:1000, most preferably in the range1:1 to 1:20. Components (1), (2) and (3) of the catalyst system canbrought together, for example, as the neat materials, as a suspension orsolution of the materials in a suitable diluent or solvent (for examplea liquid hydrocarbon), or, if at least one of the components isvolatile, by utilising the vapour of that component. The components canbe brought together at any desired temperature. Mixing the componentstogether at room temperature is generally satisfactory. Heating tohigher temperatures e.g. up to 120° C. can be carried out if desired,e.g. to achieve better mixing of the components. It is preferred tocarry out the bringing together of components (1), (2) and, (3) in aninert atmosphere (e.g. dry nitrogen) or in vacuo. If it is desired touse the catalyst on a support material (see below), this can beachieved, for example, by preforming the catalyst system comprisingcomponents (1), (2) and (3) and impregnating the support materialpreferably with a solution thereof, or by introducing to the supportmaterial one or more of the components simultaneously or sequentially.If desired the support material itself can have the properties of aneutral Lewis base and can be employed as, or in place of, component(3). An example of a support material having neutral Lewis baseproperties is poly(aminostyrene) or a copolymer of styrene andaminostyrene (ie vinylaniline).

[0045] The catalysts of the present invention can if desired comprisemore than one of the defined compounds. Alternatively, the catalysts ofthe present invention can also include one or more other types oftransition metal compounds or catalysts, for example, nitrogencontaining catalysts such as those described in our copendingapplications WO 99/12981 or GB 9903402.7. Examples of such othercatalysts include 2,6-diacetylpyridinebis(2,4,6-trimethyl anil)FeCl₂.

[0046] The catalysts of the present invention can also include one ormore other types of catalyst, such as those of the type used inconventional Ziegler-Natta catalyst systems, metallocene-basedcatalysts, monocyclopentadienyl- or constrained geometry basedcatalysts, or heat activated supported chromium oxide catalysts (e.g.Phillips-type catalyst).

[0047] The catalysts of the present invention can be unsupported orsupported on a support material, for example, silica, alumina, MgCl₂ orzirconia, or on a polymer or prepolymer, for example polyethylene,polypropylene, polystyrene, or poly(aminostyrene).

[0048] If desired the catalysts can be formed in situ in the presence ofthe support material, or the support material can be pre-impregnated orpremixed, simultaneously or sequentially, with one or more of thecatalyst components. The catalysts of the present invention can ifdesired be supported on a heterogeneous catalyst, for example, amagnesium halide supported Ziegler Natta catalyst, a Phillips type(chromium oxide) supported catalyst or a supported metallocene catalyst.Formation of the supported catalyst can be achieved for example bytreating the transition metal compounds of the present invention withalumoxane in a suitable inert diluent, for example a volatilehydrocarbon, slurrying a particulate support material with the productand evaporating the volatile diluent. The produced supported catalyst ispreferably in the form of a free-flowing powder. The quantity of supportmaterial employed can vary widely, for example from 100,000 to 1 gramsper gram of metal present in the transition metal compound.

[0049] The present invention further provides a process for thepolymerisation and copolymerisation of 1-olefins, comprising contactingthe monomeric olefin under polymerisation conditions with thepolymerisation catalyst or catalyst system of the present invention. Apreferred process comprises the steps of:

[0050] a) preparing a prepolymer-based catalyst by contacting one ormore 1-olefins with a catalyst system, and

[0051] b) contacting the prepolymer-based catalyst with one or more1-olefins, wherein the catalyst system is as defined above.

[0052] The present invention also encompasses as another aspect the useof a complex as defined above as a catalyst for the polymerisation of1-olefins.

[0053] In the text hereinbelow, the term “catalyst” is intended toinclude “catalyst system” as defined previously and also“prepolymer-based catalyst” as defined above.

[0054] The catalysts of the invention may be preformed, or may be formedin-situ by adding the components, including the activator, to thepolymerisation reactor.

[0055] The polymerisation conditions can be, for example, solutionphase, slurry phase, gas phase or bulk phase, with polymerisationtemperatures ranging from −100° C. to +300° C., and at pressures ofatmospheric and above, particularly from 140 to 4100 kPa. If desired,the catalyst can be used to polymerise ethylene under high pressure/hightemperature process conditions wherein the polymeric material forms as amelt in supercritical ethylene. Preferably the polymerisation isconducted under gas phase fluidised bed or stirred bed conditions.

[0056] Suitable monomers for use in the polymerisation process of thepresent invention are, for example, ethylene and C₂₋₂₀ α-olefins,specifically propylene, 1-butene, 1-pentene, 1-hexene,4-methylpentene-1, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene,1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene,1-heptadecene, 1-octadecene, 1-nonadecene, and 1-eicosene. Othermonomers include methyl methacrylate, methyl acrylate, butyl acrylate,acrylonitrile, vinyl acetate, and styrene. Preferred monomers forhomopolymerisation processes are ethylene and propylene.

[0057] The catalysts and process of the invention can also be used forcopolymerising ethylene or propylene with each other or with other1-olefins such as 1-butene, 1-hexene, 4-methylpentene-1, and octene, orwith other monomeric materials, for example, methyl methacryl ate,methyl acryl ate, butyl acryl ate, acrylonitrile, vinyl acetate, andstyrene.

[0058] Irrespective of the polymerisation or copolymerisation techniqueemployed, polymerisation or copolymerisation is typically carried outunder conditions that substantially exclude oxygen, water, and othermaterials that act as catalyst poisons. Also, polymerisation orcopolymerisation can be carried out in the presence of additives tocontrol polymer or copolymer molecular weights.

[0059] The use of hydrogen gas as a Means of controlling the averagemolecular weight of the polymer or copolymer applies generally to thepolymerisation process of the present invention. For example, hydrogencan be used to reduce the average molecular weight of polymers orcopolymers prepared using gas phase, slurry phase, bulk phase orsolution phase polymerisation conditions. The quantity of hydrogen gasto be employed to give the desired average molecular weight can bedetermined by simple “trial and error” polymerisation tests.

[0060] The polymerisation process of the present invention providespolymers and copolymers, especially ethylene polymers, at remarkablyhigh productivity (based on the amount of polymer or copolymer producedper unit weight of complex employed in the catalyst system). This meansthat relatively very small quantities of transition metal complex areconsumed in commercial processes using the process of the presentinvention. It also means that when the polymerisation process of thepresent invention is operated under polymer recovery conditions that donot employ a catalyst separation step, thus leaving the catalyst, orresidues thereof, in the polymer (e.g. as occurs in most commercialslurry and gas phase polymerisation processes), the amount of transitionmetal complex in the produced polymer can be very small.

[0061] Slurry phase polymerisation conditions or gas phasepolymerisation conditions are particularly useful for the production ofhigh or low density grades of polyethylene, and polypropylene. In theseprocesses the polymerisation conditions can be batch, continuous orsemi-continuous. Furthermore, one or more reactors may be used, e.g.from two to five reactors in series. Different reaction conditions, suchas different temperatures or hydrogen concentrations may be employed inthe different reactors. In the slurry phase process and the gas phaseprocess, the catalyst is generally metered and transferred into thepolymerisation zone in the form of a particulate solid either as a drypowder (e.g. with an inert gas) or as a slurry. This solid can be, forexample, a solid catalyst system formed from the one or more ofcomplexes of the invention and an activator with or without other typesof catalysts, or can be the solid catalyst alone with or without othertypes of catalysts. In the latter situation, the activator can be fed tothe polymerisation zone, for example as a solution, separately from ortogether with the solid catalyst. Preferably the catalyst system or thetransition metal complex component of the catalyst system employed inthe slurry polymerisation and gas phase polymerisation is supported onone or more support materials. Most preferably the catalyst system issupported on the support material prior to its introduction into thepolymerisation zone. Suitable support materials are, for example,silica, alumina, zirconia, talc, kieselguhr, or magnesia. Impregnationof the support material can be carried out by conventional techniques,for example, by forming a solution or suspension of the catalystcomponents in a suitable diluent or solvent, and slurrying the supportmaterial therewith. The support material thus impregnated with catalystcan then be separated from the diluent for example, by filtration orevaporation techniques. Once the polymer product is discharged from thereactor, any associated and absorbed hydrocarbons are substantiallyremoved, or degassed, from the polymer by, for example, pressurelet-down or gas purging using fresh or recycled steam, nitrogen or lighthydrocarbons (such as ethylene). Recovered gaseous or liquidhydrocarbons may be recycled to the polymerisation zone.

[0062] In the slurry phase polymerisation process the solid particles ofcatalyst, or supported catalyst, are fed to a polymerisation zone eitheras dry powder or as a slurry in the polymerisation diluent. Thepolymerisation diluent is compatible with the polymer(s) andcatalyst(s), and may be an alkane such as hexane, heptane, isobutane, ora mixture of hydrocarbons or paraffins. Preferably the particles are fedto a polymerisation zone as a suspension in the polymerisation diluent.The polymerisation zone can be, for example, an autoclave or similarreaction vessel, or a continuous loop reactor, e.g. of the typewell-known in the manufacture of polyethylene by the Phillips Process.When the polymerisation process of the present invention is carried outunder slurry conditions the polymerisation is preferably carried out ata temperature above 0° C., most preferably above 15° C. Thepolymerisation temperature is preferably maintained below thetemperature at which the polymer commences to soften or sinter in thepresence of the polymerisation diluent. If the temperature is allowed togo above the latter temperature, fouling of the reactor can occur.Adjustment of the polymerisation within these defined temperature rangescan provide a useful means of controlling the average molecular weightof the produced polymer. A further useful means of controlling themolecular weight is to conduct the polymerisation in the presence ofhydrogen gas which acts as chain transfer agent. Generally, the higherthe concentration of hydrogen employed, the lower the average molecularweight of the produced polymer.

[0063] In bulk polymerisation processes, liquid monomer such aspropylene is used as the polymerisation medium.

[0064] Methods for operating gas phase polymerisation processes are wellknown in the art. Such methods generally involve agitating (e.g. bystirring, vibrating or fluidising) a bed of catalyst, or a bed of thetarget polymer (i.e. polymer having the same or similar physicalproperties to that which it is desired to make in the polymerisationprocess) containing a catalyst, and feeding thereto a stream of monomerat least partially in the gaseous phase, under conditions such that atleast part of the monomer polymerises in contact with the catalyst inthe bed. The bed is generally cooled by the addition of cool gas (e.g.recycled gaseous monomer) and/or volatile liquid (e.g. a volatile inerthydrocarbon, or gaseous monomer which has been condensed to form aliquid). The polymer produced in, and isolated from, gas phase processesforms directly a solid in the polymerisation zone and is free from, orsubstantially free from liquid. As is well known to those skilled in theart, if any liquid is allowed to enter the polymerisation zone of a gasphase polymerisation process the quantity of liquid in thepolymerisation zone is small in relation to the quantity of polymerpresent. This is in contrast to “solution phase” processes wherein thepolymer is formed dissolved in a solvent, and “slurry phase” processeswherein the polymer forms as a suspension in a liquid diluent.

[0065] The gas phase process can be operated under batch, semi-batch, orso-called “continuous” conditions. It is preferred to operate underconditions such that monomer is continuously recycled to an agitatedpolymerisation zone containing polymerisation catalyst, make-up monomerbeing provided to replace polymerised monomer, and continuously orintermittently withdrawing produced polymer from the polymerisation zoneat a rate comparable to the rate of formation of the polymer, freshcatalyst being added to the polymerisation zone to replace the catalystwithdrawn form the polymerisation zone with the produced polymer.

[0066] For typical production of impact copolymers, homopolymer formedfrom the fust monomer in a first reactor is reacted with the secondmonomer in a second reactor. For manufacture of propylene/ethyleneimpact copolymer in a gas-phase process, propylene is polymerized in afirst reactor; reactive polymer transferred to a second reactor in whichethylene or other comonomer is added. The result is an intimate mixtureof a isotactic polypropylene chains with chains of a randompropylene/ethylene copolymer.

[0067] A random copolymer typically is produced in a single reactor inwhich a minor amount of a comonomer (typically ethylene) is added topolymerizing chains of propylene.

[0068] Methods for operating gas phase fluidised bed processes formaking polyethylene, ethylene copolymers and polypropylene are wellknown in the art. The process can be operated, for example, in avertical cylindrical reactor equipped with a perforated distributionplate to support the bed and to distribute the incoming fluidising gasstream through the bed. The fluidising gas circulating through the bedserves to remove the heat of polymerisation from the bed and to supplymonomer for polymerisation in the bed. Thus the fluidising gas generallycomprises the monomer(s) normally together with some inert gas (e.g.nitrogen or inert hydrocarbons such as methane, ethane, propane, butane,pentane or hexane) and optionally with hydrogen as molecular weightmodifier. The hot fluidising gas emerging from the top of the bed is ledoptionally through a velocity reduction zone (this can be a cylindricalportion of the reactor having a wider diameter) and, if desired, acyclone and or filters to disentrain fine solid particles from the gasstream. The hot gas is then led to a heat exchanger to remove at leastpart of the heat of polymerisation. Catalyst is preferably fedcontinuously or at regular intervals to the bed. At start up of theprocess, the bed comprises fluidisable polymer which is preferablysimilar to the target polymer. Polymer is produced continuously withinthe bed by the polymerisation of the monomer(s). Preferably means areprovided to discharge polymer from the bed continuously or at regularintervals to maintain the fluidised bed at the desired height. Theprocess is generally operated at relatively low pressure, for example,at 10 to 50 bars, and at temperatures for example, between 50 and 120°C. The temperature of the bed is maintained below the sinteringtemperature of the fluidised polymer to avoid problems of agglomeration.

[0069] In the gas phase fluidised bed process for polymerisation ofolefins the heat evolved by the exothermic polymerisation reaction isnormally removed from the polymerisation zone (i.e. the fluidised bed)by means of the fluidising gas stream as described above. The hotreactor gas emerging from the top of the bed is led through one or moreheat exchangers wherein the gas is cooled. The cooled reactor gas,together with any make-up gas, is then recycled to the base of the bed.In the gas phase fluidised bed polymerisation process of the presentinvention it is desirable to provide additional cooling of the bed (andthereby improve the space time yield of the process) by feeding avolatile liquid to the bed under conditions such that the liquidevaporates in the bed thereby absorbing additional heat ofpolymerisation from the bed by the “latent heat of evaporation” effect.When the hot recycle gas from the bed enters the heat exchanger, thevolatile liquid can condense out. In one embodiment of the presentinvention the volatile liquid is separated from the recycle gas andreintroduced separately into the bed. Thus, for example, the volatileliquid can be separated and sprayed into the bed. In another embodimentof the present invention the volatile liquid is recycled to the bed withthe recycle gas. Thus the volatile liquid can be condensed from thefluidising gas stream emerging from the reactor and can be recycled tothe bed with recycle gas, or can be separated from the recycle gas andthen returned to the bed.

[0070] The method of condensing liquid in the recycle gas stream andreturning the mixture of gas and entrained liquid to the bed isdescribed in EP-A-0089691 and EP-A-0241947. It is preferred toreintroduce the condensed liquid into the bed separate from the recyclegas using the process described in our U.S. Pat. No. 5,541,270, theteaching of which is hereby incorporated into this specification.

[0071] When using the catalysts of the present invention under gas phasepolymerisation conditions, the catalyst, or one or more of thecomponents employed to form the catalyst can, for example, be introducedinto the polymerisation reaction zone in liquid form, for example, as asolution in an inert liquid diluent. Thus, for example, the transitionmetal component, or the activator component, or both of these componentscan be dissolved or slurried in a liquid diluent and fed to thepolymerisation zone. Under these circumstances it is preferred theliquid containing the component(s) is sprayed as fine droplets into thepolymerisation zone. The droplet diameter is preferably within the range1 to 1000 microns. EP-A-0593083, the teaching of which is herebyincorporated into this specification, discloses a process forintroducing a polymerisation catalyst into a gas phase polymerisation.The methods disclosed in EP-A-0593083 can be suitably employed in thepolymerisation process of the present invention if desired.

[0072] Although not usually required, upon completion of polymerisationor copolymerisation, or when it is desired to terminate polymerisationor copolymerisation or at least temporarily deactivate the catalyst orcatalyst component of this invention, the catalyst can be contacted withwater, alcohols, acetone, or other suitable catalyst deactivators amanner known to persons of skill in the art.

[0073] Homopolymerisation of ethylene with the catalysts of theinvention may produce so-called “high density” grades of polyethylene.These polymers have relatively high stiffness and are useful for makingarticles where inherent rigidity is required. Copolymerisation ofethylene with higher 1-olefins (e.g. butene, hexene or octene) canprovide a wide variety of copolymers differing in density and in otherimportant physical properties. Particularly important copolymers made bycopolymerising ethylene with higher 1-olefins with the catalysts of theinvention are the copolymers having a density in the range of 0.91 to0.93. These copolymers which are generally referred to in the art aslinear low density polyethylene, are in many respects similar to the socalled low density polyethylene produced by the high pressure freeradical catalysed polymerisation of ethylene. Such polymers andcopolymers are used extensively in the manufacture of flexible blownfilm.

[0074] Propylene polymers produced by the process of the inventioninclude propylene homopolymer and copolymers of propylene with less than50 mole % ethylene or other alpha-olefin such as butene-1,pentene-1,4-methylpentene-1, or hexene-1, or mixtures thereof. Propylenepolymers also may include copolymers of propylene with minor amounts ofa copolymnerizable monomer. Typically, most useful are normally-solidpolymers of propylene containing polypropylene crystallinity, randomcopolymers of propylene with up to about 10 wt. % ethylene, and impactcopolymers containing up to about 20 wt. % ethylene or otheralpha-olefin. Polypropylene homopolymers may contain a small amount(typically below 2 wt. %) of other monomers to the extent the propertiesof the homopolymer are not affected significantly.

[0075] Propylene polymers may be produced which are normally solid,predominantly isotactic, poly α-olefins. Levels of stereorandomby-products are sufficiently low-so that useful products can be obtainedwithout separation thereof. Typically, usefull propylene homopolymersshow polypropylene crystallinity and have isotactic indices above 90 andmany times above 95. Copolymers typically will have lower isotacticindices, typically above 80-85.

[0076] Depending upon polymerisation conditions known in the art,propylene polymers with melt flow rates from below 1 to above 1000 maybe produced in a reactor. For many applications, polypropylenes with aMFR from 2 to 100 are typical. Some uses such as for spunbonding may usea polymer with an MFR of 500 to 2000.

[0077] Peroxide compounds may be added to ethylene or propylenepolymers. For ethylene based polymers, peroxides can be used to givecross-linking in the polymer. For the preparation of high MFR propylenepolymers, peroxide compounds may be added during extrusion forcontrolled rheology to increase the melt flow rate of polymer. Peroxideacts to break long polymer chains and has the effect of both increasingMFR and narrowing the molecular weight distribution (Mw/Mn) orpolydispersity. A typical reactor polypropylene powder with an MFR of 2g/10 min. by controlled rheology treatment with peroxide in an extrudermay form a polymer with an MFR of 2040. By varying the type, amount of,and process conditions using, peroxide, the final polymer MFR may becontrolled as known in the art.

[0078] Depending upon the use of the polymer product, minor amounts ofadditives are typically incorporated into the polymer formulation suchas acid scavengers, antioxidants, stabilizers, and the like. Generally,these additives are incorporated at levels of about 25 to 2000 ppm,typically from about 50 to about 1000 ppm, and more typically 400 to1000 ppm, based on the polymer.

[0079] In use, polymers or copolymers made according to the invention inthe form of a powder are conventionally compounded into pellets.Examples of uses for polymer compositions made according to theinvention include use to form fibres, extruded films, tapes, spunbondedwebs, moulded or thermoformed products, and the like. The polymers maybe blown into films, or may be used for making a variety of moulded orextruded articles such as pipes, and containers such as bottles ordrums. Specific additive packages for each application may be selectedas known in the art. Examples of supplemental additives include slipagents, anti-blocks, anti-stats, mould release agents, primary andsecondary anti-oxidants, clarifiers, nucleants, uv stabilizers, and thelike. Classes of additives are well known in the art and includephosphite antioxidants, hydroxylamine (such as N,N-dialkylhydroxylamine) and amine oxide (such as dialkyl methyl amine oxide)antioxidants, hindered amine light (uv) stabilizers, phenolicstabilizers, benzofuranone stabilizers, and the like. Various olefinpolymer additives are described in U.S. Pat. Nos. 4,318,845, 4,325,863,4,590,231, 4,668,721, 4,876,300, 5,175,312, 5,276,076, 5,326,802,5,344,860, 5,596,033, and 5,625,090.

[0080] Fillers such as silica, glass fibers, talc, and the like,nucleating agents, and colourants also may be added to the polymercompositions as known by the art.

[0081] The present invention is illustrated in the following Examples.

EXAMPLES Example 1 Preparation of “Ligand 1”.2,6-di-T(1,3,5-trimethyl-4-pyrazolyl)ethanimidoyl pyridine

[0082] Acetic acid (glacial, catalytic amount) was added to a solutionof diacetylpyridine (1 mmol, 1 eq.) and 4-amino-1,3,5-trimethylpyrazole(4 mmol, 4 eq.) in ethanol (10 mL, absolute). The mixture was refluxedunder nitrogen for 16 hours in a test tube containing a suspendedSoxhlet thimble filled with activated molecular sieves (3A). After thistime the mixture was concentrated under reduced pressure to give thecrude product as an orange oily solid. Trituration with petroleum etherfurnished a sandy-coloured solid which was subsequently characterised tobe the desired compound by IR and ¹H NMR spectroscopy.

Example 2 Polymerisation of Ethylene Using an Equimolar Mixture ofLigand 1 and FeCl₂.

[0083] In a glovebox, Ligand 1 (0.05 mmol, 18.9 mg) was mixed with FeCl₂(0.05 mmol) and THF (2.0 mL) was added. The mixture was stirred at roomtemperature for 1 h before the solvent was removed under vacuum toprovide a green powder.

[0084] To the powder was added toluene (6.25 mL) to form a finesuspension. From the stirred suspension a 0.5 mL aliquot (0.004 mmol)was transferred to a Schlenk tube and a solution of 10% MAO in toluenewas added (0.5 mL, 0.75 mmol). The resulting pink solution was dilutedwith 20 mL toluene and the Schlenk tube was weighed before beingevacuated and refilled with ethylene. The solution was stirred, open toan ethylene supply regulated to 1 bar pressure, for a duration of 1hour. After this time, the flask was re-weighed before quenching withacidified methanol. A weight-gain of 4.49 g was noted, corresponding toan activity of 1123 g/mmol.h.bar.

[0085] The white solid polymer product was isolated by filtration anddried overnight at 40° C. under vacuum before submitting for NMR and GPCanalysis. From the filtration washings the organic layer was isolated,and dried over MgSO₄ before removing the volatiles in vacuuo. Theresulting oil was submitted for analysis by GC-MS. GPC analysis of solidproduct: Mn=500, Mw=1500, PD=2.8. ¹³C NMR analysis of solid product(/1000C): saturated ends, 19.8; vinyl ends, 17.4; ethyl branches 1.9;butyl (and longer) branches 0.7; internal olefin 0.8 GC-MS analysis ofoil (olefin, rel. area): C6, 2.55%; C8, 8.07%; C10, 11.10%; C12, 13.16%;C14, 13.55%; C16, 13.04%; C18, 11.63%; C20, 9.26%; C22, 6.79%; C24,4.92%; C26, 2.27%; C28, 0.49%; C30, not measurable.

Example 3 Ethylene/1-hexene Copolymerisation

[0086] The polymerisation was carried out exactly as described inExample 2, except that the initially formed catalyst solution (0.5 mL oftoluene solution containing 0.004 mmol of Ligand 1+0.5 mL of 10% MAO intoluene) was diluted with 18.6 mL toluene and 0.4 mL 1-hexene (2% v/v1-hexene). The resulting solution was stirred, open to an ethylenesupply regulated to 1 bar pressure, for a duration of 1 hour. After thistime, a weight-gain of 4.79 g was noted, corresponding to an activity of1198 g/mmol.h.bar. The reaction was quenched by addition of acidifiedmethanol, and the white solid polymer product was isolated by filtrationand dried overnight at 40° C. GPC analysis showed Mn=500, Mw=1500,Mw/Mn=2.9, Mpk=500. ¹³C NMR analysis of solid product (/1000C): ethylbranches 2.2; butyl branches 1.4; internal olefin 2.0

Example 4 Preparation of 13% MAO on Silica

[0087] Toluene (200 mL) was added to a vessel containing silica (ES70Xgrade, calcined at 200° C. overnight, 20.5 g after calcination) under aninert atmosphere. The slurry was mechanically stirred and MAO (1.5M,62.1 mmol, 41.4 mL) was added via syringe. The mixture was stirred for 1hour at 80° C. before removing excess toluene and drying under vacuum toobtain 13% w/w MAO on silica in quantitative yield.

Example 5 Preparation of a Supported Catalyst

[0088] Into an vial was weighed 13% MAO on silica (100 mg, preparedaccording to Example 4). To the vial was then added toluene (2 mL) toform a slurry. In a separate vessel Ligand 1 (0.05 mmol, 18.9 mg) wasmixed with FeCl₂ (0.05 mmol) and THF (2.0 ml) was added. The mixture wasstirred at room temperature for 1 h before the solvent was removed undervacuum to provide a green powder. To the powder was added toluene (6.25mL) to form a fine suspension. From the stirred suspension a 2.75 mLaliquot (0.022 mmol of complex) was transferred to the vial containingthe toluene slurry of 13% MAO on silica. The resulting mixture wastransferred to a Schlenk tube and heated at 80° C. under nitrogen for 15minutes. On standing, the green solid settled beneath a colourlesstoluene supernatent. The solvent was removed in vacuo to provide afree-flowing green powder.

Example 6 Polymerisation using a Supported Catalyst

[0089] Into a Schlenk tube was weighed the supported catalyst preparedin Example 5 (25 mg, 0.0055 mmol Fe) and toluene (20 mL) was added.Scavenger was added (10% MAO in toluene, 1.0 mL) and the Schlenk tubewas evacuated and re-filled with ethylene. The mixture was then stirredunder 1 bar ethylene atmosphere for 1 hour, after which a mass-gain of3.93 g was recorded corresponding to an activity of 786 gPE/mmolFe/h/bar. The reaction was quenched by addition of acidified methanol,and the white solid polymer product was isolated by filtration and driedovernight at 40° C. GPC analysis showed Mn=600, Mw=1600, Mw/Mn=2.7,Mpk=600. ¹³C NMR analysis of solid product (/1000C): ethyl branches 2.3;butyl branches 0.5

Example 7 Ethylene polymerisation with a Co complex of Ligand 1

[0090] In a glovebox, Ligand 1 (0.005 mmol) was mixed with CoCl₂ (0.005mmol) in THF (1.0 mL). The mixture was stirred at room temperature for 1h before the solvent was removed under vacuum. To the residue was addedtoluene (1.0 mL) and a solution of 10% MAO in toluene (1.0 mL). Theresulting solution was stirred under an ethylene supply regulated to 0.6bar, for a duration of 10 minutes. After this time, a weight-gain of0.041 g was recorded, corresponding to an activity of 70 g/mmol.h.bar

Example 8 Preparation of “Ligand 2”

[0091] Ligand 2 was prepared using a similar procedure to that outlinedin Example 1 for Ligand 1, using dibenzoylpyridine in place ofdiacetylpyridine. The ligand was found to be >90% pure by ¹H NMR and IRanalysis.

Example 9 Ethylene Polymerisation using an Fe Complex of Ligand 2

[0092] A solution of Ligand 2 (0.5 mL THF solution containing 0.005 mmolof Ligand 2) was added to a solution of FeBr₂ (0.5 mL THF solutioncontaining 0.005 mmol FeBr₂) to form a dark-green solution. Afterstirring for 2 hours, the solvent was removed and the residue wasredissolved in toluene (1.5 mL). To this was added 10% MAO in toluene(0.5 mL) and the resulting solution was transferred to a Schlenk tubeand diluted with toluene (20 mL). The Schlenk tube was evacuated andre-filled with ethylene, then stirred under a 1 bar ethylene atmospherefor 1 hour. A weight-gain of 3.07 g was recorded corresponding to anactivity of 614 g/mmol.h.b. The reaction was quenched with acidifiedmethanol and the solid polymer product was isolated by filtration anddried overnight at 40° C. ¹³C NMR analysis of solid product (/1000C):ethyl branches 1.6; butyl branches 0.6

Example 10 Ethylene/1-hexene Copolymerisation

[0093] A solution of Ligand 2 (0.5 mL THF solution containing 0.005 mmolof Ligand 2) was added to a solution of FeBr₂ (0.5 mL THF solutioncontaining 0.005 mmol FeBr₂) to form a dark-green solution. Afterstirring for 2 hours, the solvent was removed and the residue wasredissolved in toluene (1.5 mL). To this was added 10% MAO in toluene(0.5 mL) and the resulting solution was transferred to a Schlenk tubeand diluted with toluene (20 mL) and 1-hexene (0.5 mL) was added. TheSchlenk tube was evacuated and re-filled with ethylene, then stirredunder a 1 bar ethylene atmosphere for 1 hour. A weight-gain of 4.30 gwas recorded corresponding to an activity of 860 g/mmol.h.b.

1. A metal complex being Ti[II], Ti[III], Ti[IV], Fe[II], Fe[III],Co[II], Co[III], Ni[II], Cr[II], Cr[III], Mn[II], Mn[III], Mn[IV],Ta[II], Ta[III], Ta[IV], Rh[II], Rh[II], Y[II], Y[III], Sc[II], Sc[III],Ru[II], Ru[III], Ru[IV], Pd[II], Zr[II], Zr[III], Zr[IV], Hf[II],Hf[III], HF[IV], V[II], V[III], V[IV], Nb[II], Nb[III], Nb[IV], Nb[V];ligated by a monodentate, bidentate, tridentate or tetradentate ligand,wherein at least one of the donor atoms of the ligand is a nitrogen atomsubstituted by a five-membered heterocyclic substituent joined to thenitrogen atom by a carbon atom.
 2. A complex of the Formula (1)

wherein the structure R⁵—N-G-X¹ represents a bidentate, tridentate ortetradentate ligand, in which N is a nitrogen joined to G by an iminelinkage; G is a bridging group which optionally contains a third orfourth donor atom; X¹ is —O or —S if the X¹-M bond is covalent, or ifthe X¹-M bond is dative X¹ is ═S, —PR⁷R⁸, —PR⁸R⁹, ═NR⁷, NR¹, —NR⁷R⁸ or—NR⁸R⁹; R⁵ is a five-membered heterocyclic substituent joined to thenitrogen atom via a carbon atom; R⁷ is a five-membered heterocyclicsubstituent joined to the nitrogen or phosphorus atom via a carbon atom;and R⁸ and R⁹ are hydrocarbyl or heterohydrocarbyl, substitutedhydrocarbyl or aryl substituent; M is Ti[II], Ti[III], Ti[IV], Fe[II],Fe[III], Co[II], Co[III], Ni[II], Cr[II], Cr[III], Mn[II], Mn[III],Mn[IV], Ta[II], Ta[III], Ta[IV], Rh[II], Rh[II], Y[II], Y[III], Sc[II],Sc[III], Ru[II], Ru[III], Ru[IV], Pd[II], Zr[II], Zr[III], Zr[IV],Hf[II], Hf[III], HF[IV], V[II], V[III], V[IV], Nb[II], Nb[III], Nb[IV],Nb[V]; X represents an atom or group covalently or ionically bonded tothe transition metal M; and L is a group datively bound to M, and n isfrom 0 to 5; q is 1 or
 2. 3. A complex as claimed in claim 2 wherein Xlis ═NR⁷.
 4. A complex as claimed in claim 2 or 3 wherein q is 1, and theligand is bidentate or tridentate.
 5. A complex as claimed in any one ofclaims 2 to 4 wherein R⁵ and R⁷ each independently have the structure

D, W, Y and Z are each independently selected from CR, CRR′, N, NR, O,S, PR or PRR′ where R and R′ are each independently H, C₁-C₁₀ alkyl,C₁-C₁₀ heteroalkyl or C₆-C₂₀ aryl or aralkyl, with the proviso that atleast one of D, W, Y and Z is not CR or CRR′. It is preferred that thering is heteroaromatic, with two of D, W, Y and Z being CR, and theother two being independently selected from N, NR, O or S.
 6. A complexas claimed in claim 5 wherein the ring D, W, Y and Z is heteroaromatic,with two of D, W, Y and Z being CR, and the other two beingindependently selected from N, NR, O or S.
 7. A complex as claimed inany one of claims 2 to 5 wherein R⁵ and R⁷ have the following structure:

where D¹ is NR, O or S where R is H, C₁-C₆ alkyl or C₆-C₂₀ aryl oraralkyl, and two of W¹, Y¹ and Z¹ are independently H, C₁-C₆ alkyl orC₆-C₂₀ aryl or aralkyl, whilst the third is replaced by a direct bond tothe nitrogen atom to which R⁵ or R⁷ is attached.
 8. A complex as claimedin claim 7 wherein Y¹ is replaced by the bond to the nitrogen atom towhich R⁵ or R⁷ is attached.
 9. A complex as claimed in claim 7 or 8wherein W¹ and Z¹ are C₁-C₆ alkyl or C₆-C₂₀ aryl or aralkyl.
 10. Acatalyst as claimed in any one of claims 7 to 9 wherein D¹ is NR.
 11. Acomplex represented by the general formula (m)

wherein M is Ti[II], Ti[III], Ti[IV], Fe[II], Fe[III], Co[II], Co[III],Ni[II], Cr[II], Cr[III], Mn[II], Mn[III], Mn[IV], Ta[II], Ta[III],Ta[IV], Rh[II], Rh[II], Y[II], Y[III], Sc[II], Sc[III], Ru[II], Ru[III],Ru[IV], Pd[II], Zr[II], Zr[III], Zr[IV], Hf[II], Hf[III], HF[IV], V[II],V[III], V[IV], Nb[II], Nb[III], Nb[IV], Nb[V]; X represents an atom orgroup covalently or ionically bonded to the transition metal M; Y¹ is Cor P(R^(c); Y² is —O(R⁷), —O(in which case the bond from 0 to M iscovalent), —C(R^(b))═O, —C(R^(b))═N(R⁷), —P(R)(R^(d))═N(R⁷) or—P(R^(b))(R^(d))═O; R⁵ and R⁷ are each independently five-memberedheterocyclic substituents joined to the nitrogen atom via a carbon atom;R^(a), R^(b), R^(c), R^(d) are each independently selected fromhydrogen, halogen, hydrocarbyl, substituted hydrocarbyl,heterohydrocarbyl, substituted heterohydrocarbyl or SiR′₃ where each R¹is independently selected from hydrogen, halogen, hydrocarbyl,substituted hydrocarbyl, heterohydrocarbyl and substitutedheterohydrocarbyl, and any adjacent ones may be joined together to forma ring; G is either a direct bond between Y¹ and Y², or is a bridginggroup which optionally contains a third atom linked to M when q is 1; Lis a group datively bound to M; n is from 0 to 5; and q is 1 or
 2. 12. Acomplex as claimed in claim 11 having the formula (IV)

wherein M is Ti[II], Ti[III], Ti[IV], Fe[II], Fe[III], Co[II], Co[III],Ni[II], Cr[II], Cr[III], Mn[II], Mn[III], Mn[IV], Ta[II], Ta[III],Ta[IV], Rh[II], Rh[II], Y[II], Y[III], Sc[II], Sc[III], Ru[II], Ru[III],Ru[IV], Pd[II], Zr[II], Zr[III], Zr[IV], Hf[II], Hf[III], HF[IV], V[II],V[III], V[IV], Nb[II], Nb[III], Nb[IV], Nb[V]; X represents an atom orgroup covalently or ionically bonded to the transition metal M; R^(a),R^(b) and R^(x) are each independently selected from hydrogen, halogen,hydrocarbyl, substituted hydrocarbyl, heterohydrocarbyl, substitutedheterohydrocarbyl or SiR′₃ where each R¹ is independently selected fromhydrogen, halogen, hydrocarbyl, substituted hydrocarbyl,heterohydrocarbyl and substituted heterohydrocarbyl, and R^(a) and R^(b)may be joined together to form a ring; R⁵ is a five-memberedheterocyclic substituent joined to the nitrogen atom via a carbon atom;and L is a group datively bound to M; n is from 0 to 5; and q is 1 or 2.13. A complex as claimed in claim 12 wherein the metal M is Pi, Zr, Cr,Ni or Pd.
 14. A complex as claimed in claim 12 or 13 wherein R^(a) andR^(b) are joined together to form a phenyl substituent.
 15. A complex asclaimed in claim 12 having the Formula (V)

wherein R⁵ and R⁷ are each independently five-membered heterocyclicsubstituents joined to the nitrogen atom via a carbon atom; R^(a), andR^(b) are each independently selected from hydrogen, halogen,hydrocarbyl, substituted hydrocarbyl, heterohydrocarbyl, substitutedheterohydrocarbyl or SiR′₃ where each R¹ is independently selected fromhydrogen, halogen, hydrocarbyl, substituted hydrocarbyl,heterohydrocarbyl and substituted heterohydrocarbyl, and R^(a) and R^(b)may be joined together to form a ring; M is Ti[II], Ti[III], Ti[IV],Fe[II], Fe[III], Co[II], Co[III], Ni[II], Cr[II], Cr[III], Mn[II],Mn[III], Mn[IV], Ta[II], Ta[III], Ta[IV], Rh[II], Rh[II], Y[II], Y[III],Sc[II], Sc[III], Ru[II], Ru[III], Ru[IV], Pd[II], Zr[II], Zr[III],Zr[IV], Hf[II], Hf[III], HF[IV], V[II], V[III], V[IV], Nb[II], Nb[III],Nb[IV], Nb[V]; X represents an atom or group covalently or ionicallybonded to the transition metal M; L is a group datively bound to M; n isfrom 0 to 5; and q is 1 or 2; and G31 is either a direct bond betweenthe two C═N groups, or is a bridging group which optionally contains athird donor atom when q is
 1. 16. A complex as claimed in claim 15having the Formula (V):

wherein M is Ti[II], Ti[III], Ti[IV], Fe[II], Fe[III], Co[II], Co[III],Ni[II], Cr[II], Cr[III], Mn[II], Mn[III], Mn[IV], Ta[II], Ta[III],Ta[IV], Rh[II], Rh[II], Y[II], Y[III], Sc[II], Sc[III], Ru[II], Ru[III],Ru[IV], Pd[II], Zr[II], Zr[III], Zr[IV], Hf[II], Hf[III], HF[IV], V[II],V[III], V[IV], Nb[II], Nb[III], Nb[IV], Nb[V]; X represents an atom orgroup covalently or ionically bonded to the transition metal M; R¹ andR^(b) are each independently selected from hydrogen, halogen,hydrocarbyl, substituted hydrocarbyl, heterohydrocarbyl, substitutedheterohydrocarbyl or SiR′₃ where each R′ is independently selected fromhydrogen, halogen, hydrocarbyl, substituted hydrocarbyl,heterohydrocarbyl and substituted heterohydrocarbyl, and R^(a) and R^(b)may be joined together to form a ring; wherein R⁵ and R⁷ are eachindependently five-membered heterocyclic substituents joined to thenitrogen atom via a carbon atom; and L is a group datively bound to M; nis from 0 to 5; and q is 1 or
 2. 17. A complex as claimed in claim 16wherein M is Ni or Pd.
 18. A complex having the following Formula (VII)

wherein M[T] is Ti[II], Ti[III], Ti[IV], Fe[II], Fe[III], Co[II],Co[III], Ni[II], Cr[II], Cr[III], Mn[II], Mn[III], Mn[IV], Ta[II],Ta[III], Ta[IV], Rh[II], Rh[II], Y[II], Y[III], Sc[II], Sc[III], Ru[II],Ru[III], Ru[IV], Pd[II], Zr[II], Zr[III], Zr[IV], Hf[II], Hf[III],HF[IV], V[II], V[III], V[IV], Nb[II], Nb[III], Nb[IV], Nb[V]; Xrepresents an atom or group covalently or ionically bonded to thetransition metal M; T is the oxidation state of the transition metal Mand b is the valency of the atom or group X; A¹ to A³ are eachindependently N or P or CR, with the proviso that at least one is CR; R,R⁴ and R⁶ are each independently selected from hydrogen, halogen,hydrocarbyl, substituted hydrocarbyl, heterohydrocarbyl, substitutedheterohydrocarbyl or SiR′₃ where each R¹ is independently selected fromhydrogen, halogen, hydrocarbyl, substituted hydrocarbyl,heterohydrocarbyl and substituted heterohydrocarbyl; and R and R⁷ areeach independently five-membered heterocyclic substituents joined to thenitrogen atom via a carbon atom.
 19. A complex as claimed in claim 18wherein A¹ to A³ are each independently CR where each R is as defined inclaim
 18. 20. A complex as claimed in claim 18 wherein A¹ and A³ areboth N and A² is CR.
 21. A complex as claimed in claim 18 wherein one ofA¹ to A³ is N and the others are independently CR
 22. A complex asclaimed in any one of claims 18 to 21 wherein M is Fe(II), Fe(III) orCo(II).
 23. A complex as claimed in any one of the preceding claimswherein the atom or group X is selected from chloride, bromide, hydride;hydrocarbyloxide, for example, methoxide, ethoxide, isopropoxide,phenoxide, formate, acetate, benzoate, methyl, ethyl, propyl, butyl,octyl, decyl, phenyl, benzyl, substituted hydrocarbyl,heterohydrocarbyl, tosylate and triflate.
 24. A complex as claimed inany one of the preceding claims wherein L is selected fromtetrahydrofuran, diethylether, ethanol, butanol, a primary, secondary ortertiary amine, or a phosphine.
 25. A catalyst for the polymerisation of1-olefins, or the copolymerisation of one or more 1-olefins optionallywith other unsaturated monomer, comprising the complex claimed in anyone of the preceding claims.
 26. A catalyst as claimed in claim 25comprising the defined complex together with an activator.
 27. Acatalyst as claimed in claim 26 wherein the activator compound isselected from organoaluminium compounds and hydrocarbylboron compounds.28. A catalyst as claimed in claim 26 or 27 wherein the activator is analumoxane.
 29. A catalyst as claimed in claim 26 or 27 wherein theactivator is selected from boroxines, trimethylboron, triethylboron,dimethylphenylammoniumtetra(phenyl)borate, trityltetra(phenyl)borate,triphenylboron, dimethylphenylammonium tetra(pentafluorophenyl)borate,sodium tetrakis-3,5-trifluoromethyl)phenyl]borate,H⁺(OEt₂)[(bis-3,5-trifluoromethyl)phenyl]borate,trityltetra(pentafluorophenyl)borate and trispentafluorophenyl)boron.30. A polymerization catalyst as claimed in claim 26 wherein theactivator compound is a salt of a cationic oxidising agent and anon-coordinating compatible anion.
 31. A process for polymerising orcopolymerising 1-olefins, comprising contacting the monomer underpolymerisation conditions with the polymerisation catalyst claimed inany one of claims 25 to
 30. 32. A process as claimed in claim 31 whereinthe monomer comprises one or more of ethylene, propylene, 1-butene,1-pentene, 1-hexene, 4-methylpentene-1, 1-heptene, 1-octene, 1-nonene,1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene,1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene,and 1-eicosene.
 33. A process as claimed in claim 31 wherein the monomercomprises one or more monomers selected from methyl methacrylate, methylacrylate, butyl acrylate, acrylonitrile, vinyl acetate, and styrene. 34.Homopolymers, copolymers and oligomers whenever prepared by the processclaimed in any one of claims 31 to 33.